Agilent Technologies 856290216 service manual YTO Loop Errors 317 to

313 FREQ ACC Error in LO synthesis algorithm. ERR 313 is set if a combination of sampler oscillator and roller oscillator frequencies could not be found to correspond to the required YTO start frequency. Contact the factory. This error is not applicable to HP 8560 E-Series spectrum analyzers. If it occurs in an HP 8560 E-Series spectrum analyzer, suspect a problem with the model number identification in the spectrum analyzer firmware.

314 FREQ ACC Indicates problems in the span calibration. Troubleshoot any unlocks before attempting to troubleshoot span calibration problems, because the loops must all lock in order to perform the calibration. If LO spans greater than 1 MHz are correct, check A14U114B , A14U115A, A14U116, or A14QlOl. This error message appears when the main roller oscillator sweep sensitivity is 0. A sweep ramp is injected into the locked main roller loop which should generate a negative-going ramp on MAINSENSE. ERR 314 is set if the slope of this ramp

is 0. This is an indication of an unlocked main roller loop or lack of a sweep ramp. This error is not applicable to HP 8560 E-Series spectrum analyzers. If it occurs in an HP 8560 E-Series spectrum analyzer, suspect a problem with the model number identification in the spectrum analyzer firmware.

315 FREQ ACC Indicates problems in the span calibration. Troubleshoot any unlocks before attempting to troubleshoot span calibration problems, because the loops must all lock in order to perform the calibration. If LO spans greater than 1 MHz are correct, check A14U114B , A14U115A, A14U116, or A14QlOl. This error message appears when the roller span attenuator DAC is out of range. This DAC value is recalculated each time there are changes to the span or start frequency. ERR 315 is set if this value is less than 10 or greater than 245. This error is not applicable to HP 8560 E-Series spectrum analyzers. If it occurs in

an HP 8560 E-Series spectrum analyzer, suspect a problem with the model number identification in the spectrum analyzer firmware.

316 FREQ ACC Sensitivity of main roller pretune DAC is 0. Once the main roller is locked, the MAINSENSE voltage is measured and the pretune DAC value is incremented by two. ERR 316 is set if the difference between the new MAINSENSE voltage and the previous MAINSENSE voltage is 0. This error is not applicable to HP 8560 E-Series spectrum analyzers. If it occurs in an HP 8560 E-Series spectrum analyzer, suspect a problem with the model number identification in the spectrum analyzer firmware.

YTO Loop Errors (317 to 320)

These messages indicate that the YTO main coil coarse DAC (ERR

317)or fine DAC (ERR 318) is at its limit. If error codes 300 or 301 are not present, a hardware problem exists in the YTO loop but the loop can still acquire lock. Refer to Chapter 11, “Synthesizer Section,” to troubleshoot the YTO PLL. The ADC circuit on the A3 interface assembly may also cause this error.

General Troubleshooting 7-23